Your final answer would be D.
The slope of the graph is 5/9, which means if you want an increase in 1 degree Fahrenheit, the increase is 5/9 of 1 degree Celsius.
So you can now tell that statement I is true.
This is the exactly the same as saying 1 degree Celsius increase is equal to an increase of 9/5 degrees Fahrenheit.
Since 9/5 = 1.8, that makes statement II true.
Now, statement III is not true since an increase in temperature 9/5 degrees, not 5/9 degrees Fahrenheit, is equal to an increase of 1 degree celsius.
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